Specific Aim 1: To evaluate the efficacy of CM versus nonCM conditions delivered in the context of either group (MET/CBT) or family (FFT) treatments for substance abusing adolescents. The investigators will use two substance use dependent variables. The first variable assesses the presence or absence of illegal substances in urine samples collected weekly beginning at baseline and continuing during the 12-14 weeks of scheduled treatment. Urine samples will be collected at all post-randomization assessments. Although most of the adolescents are polydrug users, marijuana is the primary drug of abuse. The investigators anticipate that once weekly urine screens will be able to detect recent marijuana use. The Time Line Follow-back (TLFB) will be used to provide weekly estimates of drug use abstinence for a period from 3 months before to 12 months after randomization. Specifically, the investigators predict that the CM versus the nonCM conditions will produce a significant main effect increase in the number of weeks of drug use abstinence during the treatment phase (i.e., months 1-4; Hypothesis 1a) and during the post treatment period (i.e., 4-12 months; Hypothesis 1b).